Senior public prosecutor David Leung Cheuk-yin argued that there were aggravating factors that warranted a heavier term.

Mr Leung said the judge had given a 50 per cent discount on the sentence to acknowledge the otherwise good character of the defendant during his 28 years' service in the police force, which was too much.

Mr Justice Tang agreed, saying the appropriate discount should not be more than four months.

Reading from a report, Mr Justice Tang noted the victim had expressed her ambivalent feelings toward the defendant, and that she did not reject him for fear her mother would get hurt and the family would not be kept together.

The judge said the trauma and distress in sex abuse cases involving children was not confined to the victim, as it also affected the parents, who may feel guilt for having entrusted the child to the abuser, or having left the child unguarded.

The court was told the victim's mother, the defendant's third wife, had since divorced him.